'Quake' reveals how eyes and ears keep us balanced

June 29, 2010
Photo: Michele Catania/Flickr

(PhysOrg.com) -- An earthquake machine has been used by vision scientists to confirm that instead of working in isolation, our visual and middle-ear systems work together, to give us an improved sense of balance.

The Earthquake machine at Questacon, the National Science and Technology Centre, has been used in groundbreaking research by vision scientists to confirm that instead of working in isolation, our visual and middle-ear systems work together, to give us an improved sense of balance.

Led by Dr Mark Edwards and Dr Michael Ibbotson, chief investigators in The Vision Centre and researchers at the Australian National University, this research has opened up various opportunities to future research, including potentially developing ways to reduce motion sickness, a phenomenon that affects millions of people.

“When we move through the world two sensory systems are activated: our visual and vestibular (or middle ear) systems,” Dr Edwards explains.

“The images on our eyes undergo complex patterns of motion, called optic-flow patterns, that indicate the type of movement we are making, e.g. radially expanding patterns indicate forward motion, and contracting patterns backward motion.”

“The consists of fluid-filled channels in our and it responds to the inertial forces produced by changes in our speed or direction of movement.”

The parental anecdotes of having children close their eyes when they are affected by motion sickness, hence removing , seems to suggest a functional interaction between these two systems.

In a unique experiment using equipment that has enthralled thousands of visitors to Questacon, young and old, Dr Edwards and Dr Ibbotson have demonstrated both our visual and vestibular systems are far more closely interconnected than was previously thought.

“The sense of balance comes from both our sight and vestibular system working in combination, but it has never been previously demonstrated that the two are functionally connected in humans,” Dr Edwards says.

The research was conducted using a most unusual piece of research equipment, the Earthquake machine, which simulates the effect of an earthquake. Using it, the research team was able to measure the sensitivity of volunteers to optic-flow patterns when they were physically moved in a direction that was either consistent or inconsistent with that pattern being received by the eyes. For example, sensitivity to a radially-expanding pattern when they were moved either forwards (consistent) or backwards (inconsistent).

“We predicted that if the visual and optic-flow systems were functionally linked, then sensitivity to motion would be greater when the two signals were consistent, and the two signals could facilitate each other, compared to when they were inconsistent. This is the pattern of results we obtained.”

The ability of the visual system and the inner ear to work together would be of greatest importance under conditions where both signals are relatively weak, for example, when produced by body sway while maintaining balance. It may also be of importance in dealing with effects such as .

The team is also considering the possibility that this crosstalk between the senses is different for each individual, depending upon their need to maintain balance. A next step is to find out how these systems actually talk to each other so we can fine tune our ability to maintain balance.

Related Stories

Recommended for you

A sodium surprise: Engineers find unexpected result during cardiac research

July 20, 2017
Irregular heartbeat—or arrhythmia—can have sudden and often fatal consequences. A biomedical engineering team at Washington University in St. Louis examining molecular behavior in cardiac tissue recently made a surprising ...

Want to win at sports? Take a cue from these mighty mice

July 20, 2017
As student athletes hit training fields this summer to gain the competitive edge, a new study shows how the experiences of a tiny mouse can put them on the path to winning.

'Smart' robot technology could give stroke rehab a boost

July 19, 2017
Scientists say they have developed a "smart" robotic harness that might make it easier for people to learn to walk again after a stroke or spinal cord injury.

Engineered liver tissue expands after transplant

July 19, 2017
Many diseases, including cirrhosis and hepatitis, can lead to liver failure. More than 17,000 Americans suffering from these diseases are now waiting for liver transplants, but significantly fewer livers are available.

Lunatic Fringe gene plays key role in the renewable brain

July 19, 2017
The discovery that the brain can generate new cells - about 700 new neurons each day - has triggered investigations to uncover how this process is regulated. Researchers at Baylor College of Medicine and Jan and Dan Duncan ...

New animal models for hepatitis C could pave the way for a vaccine

July 19, 2017
They say that an ounce of prevention is worth a pound of cure. In the case of hepatitis C—a disease that affects nearly 71 million people worldwide, causing cirrhosis and liver cancer if left untreated—it might be worth ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.